/Engine/Plugins/Online/OnlineFramework/Source/Lobby/Public/LobbyBeaconClient.h
Tell the server to set a party owner
virtual void SetPartyOwnerId ( const [FUniqueNetIdRepl](API\Runtime\Engine\GameFramework\FUniqueNetIdRepl) & InUniqueId, const [FUniqueNetIdRepl](API\Runtime\Engine\GameFramework\FUniqueNetIdRepl) & InPartyOwnerId )